Systems, apparatuses and methods for assaying biological fluids, as well as test elements for use therein, are well known. For example, electrochemical-based testing methods are known that generally rely upon a correlation between a current (amperometry), a potential (potentiometry) or an accumulated charge (coulometry) and an analyte concentration, typically in conjunction with a reagent that produces charged-carriers when combined with an analyte of interest. Known test elements for conducting such electrochemical tests are typically disposable biosensor test strips having a detection reagent that chemically reacts with the analyte of interest in a biological fluid sample. Generally, the test element is attached/inserted into a test meter that can measure the reaction between the analyte and the detection reagent to determine the analyte concentration.
In general, test elements have a reaction zone that contains measurement electrodes that come into direct contact with the biological fluid sample. In some amperometric and coulometric electrochemical measurement systems, the measurement electrodes are attached to electronic circuitry in a test meter that supplies an electrical potential to the measurement electrodes and measures the response of the electrochemical sensor to this potential (e.g., current, impedance, charge, etc.). This response is proportional to the analyte concentration.
For test elements in which the electrodes, traces and contact pads are made from electrically conductive thin films (e.g., noble metals, carbon ink, silver paste, etc.), resistivity of the conductive traces that connect the reaction zone of the test element to the electronic circuitry in a test meter can measure several hundred Ohms or more. This resistance causes a potential drop along the length of the traces, such that the potential presented to the measurement electrodes in the reaction zone is less than the potential applied by the test meter to contact pads of the test strip in a contact zone of the test strip. Physical damage to test elements, such as abrasion, cracks, scratches, chemical degradation, etc. can occur during manufacturing, shipping, storage or user mishandling. Such defects can damage test elements so that they may present an extremely high resistance or even an open circuit to the test meter. Such changes in the trace resistance can prevent the test meter from performing an accurate test. Accordingly, a need exists for improved test elements capable of confirming, checking or verifying test element integrity prior to their individual use.